Jam lover's one way of working with damsons originally (3)
I believe the answer is:
mod
'jam lover's' is the definition.
(a mod might be a fan of the band The Jam)
'one way of working with damsons originally' is the wordplay.
'one way of working' becomes 'mo' (abbreviation for modus operandi).
'with' says to put letters next to each other.
'originally' indicates taking the first letters.
The first letter of 'damsons' is 'd'.
'mo'+'d'='MOD'
(Other definitions for mod that I've seen before include "Gaelic literary festival" , "ministry" , "Rocker's rival?" , "1960s teenager" , "Meeting of the Scottish" .)